An unreliable witness and an overzealous detective hinder a murder investigation; a con artist scam leads the squad to a sex-slavery operation; McDowell agrees to join Sipowicz and Theo at a theme park.
McDowell and Ortiz investigate the death of a woman found in her apartment, where an ex-con neighbor is suspect. The investigation into Scott's murder points towards his friend. Andy thinks about the future. Rita meets John's father.
When NYPD Auxiliary Police Officer Heather Peterson is murdered, the detectives find her diary that details the sexual habits of the police officers at the 15th precinct. These findings cause the detectives to suspect the officers of the 15th precinct had something to do with her death, and the investigation of the cops cause tension between the officers and the detectives.
IAB start interviewing the officers who were in the diary, and Sipowicz and Clark are blamed as rats. A social worker appears to have taken her own life. A former cop wants his ashes buried at the precinct.
Andy and Theo move out. Tony thinks about calling it a day with his ex-wife. Sipowicz and Clark Jr look into the threats made to Clark Sr. A distressed, schizophrenic young man keeps saying "she can't breathe".